Toothbrush

ABSTRACT

A toothbrush head having elastomeric oral hygiene parts in the form of elastomeric strips aligned non-perpendicular to the length direction of the head. Preferably adjacent pairs of strips are linked to form a strip of “V” ( 32 A,  32 B) cross section. Preferably the head comprises flexibly linked segments ( 14, 15 ) and is flexibly linked to the toothbrush handle.

This invention relates to toothbrush heads, in particular to toothbrushheads having elastomeric oral hygiene parts on their head to contact theteeth and gums, and especially to the heads of such toothbrushes.

Toothbrushes are known articles, generally comprising a head and a griphandle, disposed along a longitudinal head-handle direction, with a necklongitudinally in between the head and handle. The head is generallyelongate between a tip distant from the handle and a base closest to thehandle, and is flattened in its thickness direction generallyperpendicular to the longitudinal direction, and has a widthwisedirection perpendicular to both the longitudinal and thicknessdirections.

The head normally has a face from which one or more oral hygiene partssuch as tooth-cleaning parts, e.g. bristles project in a bristledirection generally perpendicular to the longitudinal direction, and anopposite face, these faces being joined by edge surfaces. As the face isnormally generally planar bristles project in a bristle directiongenerally perpendicular to the face. The head may be an integral partwith the handle, or may be replaceably attachable to the handle orhandle-neck unit. Toothbrushes are generally made from hard plasticsmaterials such as polypropylene, but many these days are two-component,i.e. having a hard plastics skeleton and one or more softer elastomericparts e.g. to enhance the grip handle and/or to provide elastomericparts of flexible links. Among such two component toothbrushes are theapplicant's Dr BEST™ and AQUAFRESHT™ range of toothbrushes.

Toothbrushes having elastomeric oral hygiene parts on their head tocontact the teeth and gums are known. The term “oral hygiene part” asused herein refers to a part which contributes to oral hygiene, forexample by cleaning the teeth, gums or other oral tissues, and/ormassaging the gums or other oral tissues. GB-A-2 040 161 discloseslongitudinally extending elastomer strips. GB-A-2 214 420 andWO-A-00/49911 both disclose a toothbrush having a head from whichproject small rubber pyramids. GB-A-214 701 discloses a toothbrushhaving oral hygiene parts comprised of strips of crepe rubber, in onetheoretically discussed embodiment of which the strips may have bristlessandwiched between the strips of crepe rubber. EP-A-0 360 766 disclosessmall rubber cylinders with knobbed ends. U.S. Pat. No. 4,128,910discloses a toothbrush having rubber oral hygiene parts of variouspyramid and ridge shapes. U.S. Pat. No. 4,277,862 discloses a toothbrushhaving resilient gum massage parts along the outer edges of the bristlepattern. U.S. Pat. No. 4,288,883 discloses rubber cones. U.S. Pat. No.5,040,260 discloses a toothbrush having a head from which extend smallrubber cones. WO-A-96/15696 discloses a toothbrush head provided withstrips of a flexible and resilient material, typically a non-elastomericnylon material, and typically aligned either perpendicular to orparallel to the longitudinal direction. WO-A-96/28994 discloseselastomer bars extending perpendicular to the longitudinal direction andparallel to the edges of the head in combination with bristle “bars”having an elongate cross section cut across the bristle direction, andalso discloses a curved rubber “scooping bar” at the tip end of thehead. WO-A-97/16995 discloses elastomer “bristles”. WO-A-98/18364discloses tooth polishing pads or finger-like structures. WO-A-99/37181discloses an outer ring of rubber fingers surrounding an inner densepack of bristles. WO-A-00/64307 discloses rubber bars with a generallytriangular cross section. WO-A-00/76369 discloses elastomeric massagingparts with rotational symmetry through an angle of 120° or less e.g.cylinders. WO-A-01/21036 discloses a longitudinally extendingelastomeric wall-like member running for at least half the length of thehead.

Such elastomeric parts are provided inter alia to massage and/orstimulate the gums and to clean the teeth and gums. Often they areprovided on a toothbrush head in a cluster together with conventionalbristles, e.g. made of known nylon materials, to supplement and enhancethe tooth and gum cleaning effect of the bristles.

“Flexible head” toothbrushes are also known with two or more flexiblyand resiliently linked segments in their head, i.e. a “multiple segment”head, see for example WO-A-92/17093, WO-A-96/02165, WO-A-97/07707 andWO-A-97/24048. It is also known to provide toothbrushes with a headwhich is connected by a flexible link to the handle, see for exampleWO-A-92/17092 and WO-A-97/24949. It is also known to providetoothbrushes with a head which is connected by a flexible link to thehandle, and which also has two or more flexibly and resiliently linkedsegments in its head, see for example WO-A-98/37788.

The content of these patent publications is incorporated herein byreference.

It is an object of this invention to provide an improved construction ofa toothbrush having the above-mentioned elastomeric oral hygiene partson their head.

According to one aspect of this invention a toothbrush head is provided,comprising two or more segments flexibly and resiliently linked to eachother, one or more of the segments having a face on which is mounted oneor more elastomeric oral hygiene part.

Preferably the segments are longitudinally sequentially disposed.

Preferably the flexible head comprises two segments being asubstantially rigid base segment adjoining the toothbrush neck andextending from the base end of the head to a resilient flexible linksituated between the base end and the tip, and a tip segment extendingfrom the tip of the head to the link, the tip segment being flexibly andresiliently linked at the link to the base segment.

Herein the term “tip segment” refers to that segment(s) of amultiple-segment toothbrush which is closest to the tip of the head.Herein the term “base segment” refers to that segment(s) of amultiple-segment toothbrush which is closest to the tip of the head.Preferably the toothbrush head has only two such segments, being a tipsegment and a base segment, linked by the resilient flexible link.

Preferably the base segment extends for at least 50%, suitably at least60%, for example at least 75% of the distance between the base end ofthe head and the tip of the head.

When not being used, i.e. when at rest not being subjected to the forcesof toothbrushing, the respective faces of adjacent segments may besubstantially coplanar, or alternatively the respective faces ofadjacent segments, particularly longitudinally adjacent segments, mayform an angle of less than 180° with each other. For example therespective faces of the tip segment and of the base segment in such aflexible head may be substantially coplanar, i.e. with a substantially180° angle between them. Preferably the face of the tip segment may forman angle of less than 180° with the face of the base segment, e.g.150°-179°, suitably 155°-170°.

Such a flexible head may be as disclosed in above-mentionedWO-A-92/17093, WO-A-97/07707, WO-A-97/24048 and WO-A-96/02165. Typicallyin such a flexible head the resilient flexible link between two adjacentsegments of the head may comprise a region between the segmentsincluding elastomeric material. Typically the construction of such alink may comprise an aperture in the head between the segments, bridgedby a flexible strip of plastic material. For example a face of the headmay have one or more groove therein, the lands on each side of thegroove comprising the segments, and flexible resilient linking occursabout a thinned region, e.g. a thin strip of head material at the bottomof the groove, the groove containing an elastomeric material. There maybe such a groove in one face of the head, e.g. that from which the oralhygiene part(s) extend, or in the opposite face, or in both faces, suchthat the thin strip of head material is at the respective bottom of bothof the grooves. In one or more place such a groove may cut completelythrough the thickness of the toothbrush head.

Such a flexible head may be permanently attached to the handle, e.g.integrally made together with the handle. Alternatively the head may bereplaceably attachable to the handle. Suitably there is a neck betweenthe head and handle. The head and handle are disposed along a toothbrushlongitudinal direction, with such a neck longitudinally between the headand handle.

According to another aspect of this invention a toothbrush is providedwith a head which is connected by a resiliently flexible link to thehandle, and having a face on which is mounted one or more elastomericoral hygiene part.

The construction of flexible link between the head and handle may forexample be as disclosed in WO-A-92/17092 and WO-A-97/24949, for examplecomprising a thin, flexible plastic material spine linking the head andhandle, usually linking the head and neck, the spine being wholly orpartly surrounded by a mass of elastomer, e.g. a mass of elastomer witha generally spherical profile.

The toothbrush head of this second aspect may be a flexible head asdescribed above, for example comprising two or more segments flexiblyand resiliently linked to each other, one or more of the segments havinga face on which is mounted one or more elastomeric oral hygiene part,for example comprising two respective longitudinally disposed tip andbase segments. The flexible link to the handle will normally be betweenthe base segment and the handle. The overall construction of such atoothbrush may be for example as disclosed in WO-A-98/37788.

The one or more elastomeric oral hygiene part may be mounted on one ormore segment of such a flexible toothbrush head, for example on the tipsegment and/or base segment of a two segment flexible head.

The one or more elastomeric oral hygiene part in the above aspects ofthe invention may be of known type, for example one or more of the knownsmall rubber cones, small rubber pyramids, strips of rubber, elastomer“bristles”, tooth polishing pads or finger-like structures, elastomerbars e.g. of a generally rectangular cross section, elastomericmassaging parts with rotational symmetry through an angle of 120° orless e.g. cylinders, a resilient elastomer wall-like member, and smallrubber cylinders with knobbed ends etc. as mentioned above.

One preferred form of elastomeric oral hygiene part comprises anelastomeric finger, for example a cylinder typically 0.5-2.0 mmdiameter, preferably ca. 1-1.5 mm diameter, and about the same length asconventional bristles. All of a plurality of such fingers may have thesame length, or cylinders of different lengths may be used. Such fingersmay have gently tapering sides, i.e. being slightly conical, i.e.narrower at the end remote from the face, and they may have convexlyrounded ends remote from the face, and/or may have a small concavity ordimple at the end remote from the face.

For example a plurality of such fingers may be mounted in a polygonalcluster on the tip segment of a flexible head as described above, forexample a cluster comprising a polygon of 5 to 8, preferably 6 or 7,such cylinders surrounding a central cylinder.

In a further aspect, this invention also provides novel constructions ofelastomeric oral hygiene part suitable for mounting on the face of atoothbrush head, particularly the toothbrush heads described abovehaving multiple flexibly-linked segments and/or a flexible link betweenthe head and handle.

For example according to this further aspect of this invention, atoothbrush head is provided having a face, and having an elastomericoral hygiene part mounted thereon, characterised in that the elastomericoral hygiene part comprises an adjacent pair of elastomeric strips whicheach project from the face of the toothbrush head in a strip lengthdirection, each elastomeric strip having a strip width directiongenerally perpendicular to the strip length direction the strip widthdimension being less than the strip length direction, and a stripthickness direction generally perpendicular to both the strip length andstrip width direction, the strip thickness dimension being less than thestrip width direction, the adjacent strips being aligned so that theirrespective width directions converge to define an angle of 180° or lessbetween them.

Typically the strip width dimension is 0.30 or less of the strip lengthdimension, for example 0.25 or less, preferably 0.2 or less. The stripthickness may for example be 0.1-1.5 mm, typically 0.75-1.25 mm e.g.0.9+/−0.1 mm.

Typically the width directions converge to define an angle between themof 120° or less, preferably between 100° to 40°, more preferably between90° to 60°, for example ca. 70°.

Suitably the cross section of each strip cut across the strip lengthdirection may be generally straight linear, e.g. each strip may have agenerally parallel sided cross section. For example in cross sectioneach strip may be generally rectangular, e.g. with one or more roundedend, or parallelogram shaped. Alternatively the cross section of eachstrip cut across the strip length direction may present a concave orconvex curved side facing outwardly, for example a concave part-circularor part-oval curved surface.

The width directions of such longitudinally adjacent strips may convergein a direction transverse to the longitudinal direction, either awayfrom or toward the centre of the head, suitably in a transversedirection generally perpendicular to the longitudinal direction.Alternatively the respective width directions of widthwise adjacentstrips may converge in a direction parallel to the longitudinaldirection, either toward or preferably away from the handle.

Preferably two such adjacent strips are linked such that the pair ofstrips comprise a single strip with a cross section, cut across thestrip length direction, which is “V” shaped, i.e. chevron shaped, thelimbs of the chevron converging to define the said angle of less than180° between them.

Typically the limbs may converge to define an angle between them of 120°or less, preferably between 100° to 40°, more preferably between 90° to60°, for example ca. 70°.

Typically the strip width dimension of each of the two adjacent linkedstrips, i.e. as measured from the link between the strips to the edgefurthest from the link is 0.30 or less of the strip length dimension,for example 0.25 or less, preferably 0.2 or less.

Suitably the outer surface of each limb of the chevron cut across thestrip length direction may be generally straight linear, e.g. each limbmay have a generally parallel sided cross section. Alternatively eachlimb of the chevron may present a curved side facing outwardly, forexample a concave or convex part-circular or part-oval curved surface.The chevron may have a sharply angled point, or alternatively the pointmay be rounded.

The chevron may for example point in a direction transverse to thelongitudinal direction, preferably generally perpendicular to thelongitudinal direction, either outwardly from or preferably inwardlytoward the longitudinal axis of the toothbrush head, or respectivechevrons pointing in both directions may be used in combination. Aplurality of such chevron sectioned elastomeric strips pointing in adirection transverse to the longitudinal direction may be providedsequentially longitudinally with their points pointing inwardly, andwith the edges of the limbs of the chevron adjacent to the edge of theface of the head on which it is mounted.

A plurality of such chevron sectioned strips may comprise discreteindividual chevron sectioned strips or alternatively they may be linkedinto a zig-zag arrangement.

Alternatively for example the chevron may point in a direction generallylongitudinally, e.g. substantially parallel to the longitudinaldirection, either toward or preferably away from the handle, preferablycoaxial with the longitudinal axis of the head. For example a pluralityof such chevron sectioned elastomeric strips with their points pointingin a direction parallel to the longitudinal direction away from thehandle may be provided longitudinally adjacent to each other, with thepoint of one chevron nesting into the concave “bite” of a longitudinallyadjacent another.

One or more chevron sectioned strip may be disposed in variousarrangements on the toothbrush head. For example in a multiple segmentflexible head one or more such chevron sectioned elastomeric strippointing in a direction transverse to the longitudinal direction asdescribed above may be provided on the base segment. For example in amultiple segment flexible head one or more such chevron section strippointing in a direction parallel to the longitudinal direction, eithertoward or preferably away from the handle, may be mounted on the tipsegment. For example in a multiple segment flexible head one or moresuch chevron section strip pointing in a direction parallel to thelongitudinal direction, either toward or preferably away from thehandle, may be mounted on the base segment.

Two or more of the different types of oral hygiene parts described abovemay be used, for example a combination of one or more of the abovedescribed known cylinders, cones, strips etc. together with one or morepair of convergent strips, or chevron sectioned strip of this invention.For example a chevron sectioned strip, with its point pointing in thedirection away from the handle to a point, may have its point flanked oneach widthwise side by one or more strip of elastomeric material withits width direction substantially parallel to the outer surface of thelimbs of the chevron, e.g. with its width direction aligned at a similarangle relative to the longitudinal axis of the head, as the limbs of achevron.

Preferably the elastomeric oral hygiene part projects to the same orapproximately the same length from the face as conventional bristles.Alternatively the part may project to a longer or shorter length fromthe face than any bristles which may be present on the face.

An elastomeric oral hygiene part may project substantially perpendicularto the face, or may be inclined. A suitable angle of inclination is ca.80°, for example leaning so that the end of the oral hygiene part remotefrom the face is closer to the handle or the tip than is the end closestto the face.

The above-described novel elastomeric oral hygiene part(s) are suitablefor use with the above-described toothbrush head comprising two or moresegments flexibly and resiliently linked to each other, or/and connectedby a resiliently flexible link to the handle.

In the toothbrush head of all aspects of this invention theabove-described elastomeric oral hygiene part(s), whether of known typeor of the novel type disclosed above may be combined in a cluster withbristles in various arrangements. In such a cluster the elastomeric oralhygiene part(s) may supplement the cleaning action of the bristles byfor example massaging the gums. Some suitable examples of arrangementsare described below.

For example the one or more elastomeric oral hygiene part may be mountedonly on the tip segment, the other segment(s) having only bristles astheir oral hygiene part. For example alternatively the one or moreelastomeric oral hygiene part may be mounted only on the base segment,the other segment(s) having only bristles as their oral hygiene part.For example the head may consist of a flexibly linked tip segment andbase segment, the tip segment may have bristles but no elastomeric oralhygiene parts mounted thereon, and the base segment may have elastomericoral hygiene parts and optionally bristles thereon.

For example when the elastomeric oral hygiene parts comprise one or moreabove-described pair of convergent strips, for example the abovedescribed chevron sectioned strip, one or more bristle tuft may belocated between the converging strips or limbs of the chevron, e.g. inthe bite between converging limbs of a chevron.

For example if elastomeric oral hygiene parts are arranged as describedabove along the widthwise opposite edges of the head, then between theseedges, i.e. about the central area of the head, there may be bristles.

Bristles of the toothbrush head may be arranged on the head in tuftscontaining a plurality of bristles. Such bristle tufts may be ofcircular cross section cut across the bristle direction, for examplehaving a diameter similar to that of conventional circular cross sectiontufts. Alternatively the tufts may have a non-circular cross section.

For example the tufts may have a non-circular section, e.g an elongatenon-circular cross section, cut across the bristle direction. Examplesof elongate cross sections include a so called bristle “bar” which has agenerally rectangular cross section, typically with rounded ends, or anoval cross section. The ends of such an elongate “bar” may be triangularor wedge shaped, e.g the bar may be rectangular with one or moretriangular or wedge shaped end, or diamond shaped (i.e. two base-to-basetriangles) to assist the tuft in “nesting” with an adjacent elastomericstrip such as a chevron-sectioned strip. The long dimension of such anelongate cross section may for example be aligned substantiallyperpendicular to or parallel to the longitudinal axis of the toothbrushhead, or to an adjacent part of an edge of the face. For examplealternatively the long dimension of an elongate cross section may bealigned at an angle which is neither perpendicular nor parallel to thelongitudinal direction nor parallel to the closest adjacent part of theedge of the face. For example the long dimension may be aligned at anangle between 30° to 60° to the toothbrush head longitudinal direction,for example between 40° to 50°, e.g. ca. 45° to the longitudinaldirection. The long dimensions of the cross sections of widthwiseseparated, e.g. adjacent, such tufts may converge, for example towardthe tip of the head. For example if an above-mentioned elastomeric oralhygiene part in the form of a pair of strips of converging widthdirections, or a chevron sectioned strip, is present, such a tuft mayhave its long dimension aligned substantially parallel to the widthdirection of the strip or limb of the chevron.

For example a tuft may have a non-circular cross section which has anangle which can nest into the bite between a pair of convergentelastomeric strips, e.g. of a chevron-sectioned strip. Such a tuft mayfor example have a triangular cross section cut across the bristledirection. The apex angle of such a tuft may correspond to the anglebetween the limbs of a chevron-sectioned strip into which it nests, orcorresponding to the angle of an adjacent elastomeric strip. Examples oftriangular sectioned tufts are for example disclosed in WO-A-9703587.

Alternatively such a tuft may have a cross section which is a chevronshape cut across its bristle direction, the limbs of the chevron formingan angle of less than 180° between them. Typically the angle between thelimbs may be 120° or less, preferably between 100° to 80°, for exampleca. 90°.

For example such a chevron sectioned tuft may be aligned so that itpoints in the longitudinal direction, preferably away from the handle.For example a chevron sectioned tuft may be nested with anabove-mentioned chevron sectioned elastomeric oral hygiene part, eitherwith the tuft nesting into the elastomeric part, or vice versa. Forexample there may be a longitudinal sequence of alternating of one ormore such chevron sectioned tuft and one or more such chevron sectionedelastomeric oral hygiene part.

Bristles, whether in tufts of circular or non-circular cross section,may be mounted in the head with their bristle direction substantiallyperpendicular to the face.

In a further aspect the invention provides a novel toothbrush head, onwhich is mounted one or more elastomeric oral hygiene part, and on whichbristles which lean at a non perpendicular angle to the face, so thatthe end of the bristle remote from the face is distanced longitudinally(which is preferred) or widthwise relative to the end closest to theface, are also mounted.

The head of the toothbrush of this aspect of the invention may be a headas described above, e.g. comprising two or more segments flexibly andresiliently linked to each other, one or more of the segments having aface on which is mounted the said one or more elastomeric oral hygienepart, and/or said head being connected by a resiliently flexible link tothe handle. There may be both bristles and elastomeric oral hygieneparts on the faces of all segments, or bristles and oral hygiene partsmay be respectively disposed on the faces of respective differentsegments.

For example bristles may be arranged in a tuft having an elongate crosssection, e.g. as described above, and the angle at which the bristleswithin the tuft lean may vary with distance along the long dimension ofthe elongate cross section. For example at each end of the longdimension the bristles may lean in opposite directions away from thelongitudinal centre of the tuft, and at the mid point of the longdimension the bristles may be perpendicular to the face, and atintermediate points between each end and the mid point the bristles maylean at an intermediate angle. The bristles consequently “fan”longitudinally away from the central position. The long dimension ofsuch a tuft may be aligned generally parallel to the longitudinal axis,e.g. parallel to an adjacent part of the edge of the face. For examplebristles in such an arrangement may fan out from this mid point.

For example the toothbrush head may have a face on which is mounted oneor more elastomeric oral hygiene part, together with at least twowidthwise separated tufts of bristles, the bristle directions of onesuch tuft being such that the end of the bristles remote from the faceis distanced longitudinally relative to the end closest to the face, andthe bristle directions of the other such tuft being such that the end ofthe bristles remote from the face is distanced longitudinally relativeto the end closest to the face but in the opposite longitudinaldirection, or is perpendicular to the face.

In addition to being separated widthwise such tufts may also beseparated longitudinally.

For example tufts of bristles in a widthwise outer longitudinal row ofbristles may lean in a first direction, and tufts of bristles in one ormore widthwise inward row, e.g. in an a widthwise adjacent row, may leanin a second direction such that as viewed from a direction parallel tothe widthwise direction of the head the alignment of the tufts is seento converge or diverge, and/or preferably to cross.

The first and second directions may both be non-perpendicular to theplane of the face, alternatively a first or second direction may be adirection perpendicular to the face, and the respective second or firstdirection may be a non-perpendicular direction.

For example tufts of bristles may be arranged in substantiallylongitudinal rows, e.g. parallel to an edge of the face, and tufts in arow may be aligned, e.g. to lean non-perpendicularly in a firstdirection, for example toward or away from the tip of the head, andtufts in another longitudinal row may be aligned, e.g. to leannon-perpendicularly in a second direction opposite to the firstdirection, for example toward or away from the base of the head.

Typical non-perpendicular angles of lean may be in the range 70°-85°,typically ca. 80°, to the plane of the face, typically leaning towardthe tip or the base of the head, for example leaning parallel to thelongitudinal direction or parallel to an edge of the head.

Examples of such “crossed” bristles are disclosed in WO-A-99/23910,FR-A-2 624 360, U.S. Pat. No. 3,085,273, U.S. Pat. No. 5,274,873, U.S.Pat. No. 4,776,054, U.S. Pat. No. 3,085,273, U.S. Pat. No. 2,242,743,DE-G-82 02 897.4 among others, although without the presence ofelastomeric oral hygiene parts, and their teaching is incorporatedherein by way of reference.

With the above-described leaning bristles, the elastomeric oral hygienepart(s) may be of the known or novel types referred to above, and/or thetoothbrush head may be the above-described toothbrush head comprisingtwo or more segments flexibly and resiliently linked to each other,or/and connected by a resiliently flexible link to the handle.

Bristles present on the face of the toothbrush head may be all ofsubstantially the same length, alternatively the bristles may be ofdiffering lengths. One preferred such embodiment is the so called known“interdent” configuration in which sequentially longitudinally disposedtufts or groups of tufts alternate between greater and lesser lengths.

The face from which the elastomeric oral hygiene part(s) and bristles ifpresent project may be planar. Alternatively the face may be non-planar,e.g. as disclosed in WO-A-9625866. Alternatively the face may benon-planar. For example the face may be stepped to define two or morelevels relative to the opposite face. For example the face may comprisea central longitudinally aligned raised platform, flanked on bothwidthwise adjacent sides by relatively lower areas.

The term “elastomeric material” as used herein is synonymous with suchterms as “elastomer”, “elastomer material”, “rubber” and “rubberymaterial”. The term includes synthetic and natural elastomers. The termincludes materials which on compression deform and spring backimmediately or very quickly on release of the pressure. Preferably theelastomeric material is a thermoplastic elastomeric material tofacilitate injection moulding.

For the above-described elastomeric material oral hygiene parts,preferably the elastomeric material has a hardness from about 10 toabout 90 Shore A, more preferably 50 Shore A or less, e.g. from about 14to about 35 Shore A. Suitable elastomeric materials include thoseavailable under the trade names Megol and Santoprene, and siliconeelastomeric materials may also be used. Other suitable elastomericpolymers include styrenes (for example styrene ethylene butadienestyrene, or styrene butadiene styrene). Other suitable elastomericmaterials are disclosed in the state of the art referred to above.

The plastics material of the toothbrush, and the elastomeric material ofthe above described flexible links, whether present in the link betweenthe base and tip segments of the head when this is a composite segment,or in the link between the head and neck when this is a compositesegment, may be plastics and elastomeric material as commonly used intwo-component toothbrushes, e.g. that described in EP-A-0 336 641, whichcan be bonded to plastics materials used for toothbrush handlemanufacture. Such an elastomeric material can be injected into thetoothbrush mould shortly after injection moulding of the plasticsmaterial parts of the toothbrush so that the hot plastics material fusesand bonds with the elastomeric material. This is a generally knownprocess and many toothbrushes are known which use this technology forexample those sold under the names Dr BEST™ and AQUAFRESH™ by theapplicant and its related companies.

Suitable plastics materials include those with a modulus of elasticityof at least about 500 Mpa, preferably at least about 1000 Mpa, thesebeing conventional in the toothbrush art. Suitable materials include forexample, polyamides and polypropylenes. An example of a suitablepolyamide is the material ‘Ultramid B3™’ (marketed by BASF, FederalRepublic of Germany), having a modulus of elasticity (DIN 53452) of3000. An example of a suitable polypropylene is the material ‘Novolene1100 HX™’ (marketed by BASF, Federal Republic of Germany), which is ahomopolymer and has a modulus of elasticity (DIN 53457) of 1400. Such apolypropylene homopolymer may optionally be used in admixture with apolypropylene block co-polymer, such as the material ‘Novolene 2500 HX™’(marketed by BASF, Federal Republic of Germany), for example in an 80:20mixture by weight (1100 HX:2500 HX). Other suitable polypropylenesinclude Polypropylene PM 1600™ (marketed by Shell) and having a modulusof elasticity (ISO 178) of 1500 Mpa and Apryl 3400 MAI™ from ElfAtochem, Novolen 2400 H and 1106, and Borealis HG 365 P.

The toothbrush of the invention may be made by generally conventionalinjection moulding techniques, for example in which a plastics material“skeleton” is first made by injection moulding, leaving apertures in theskeleton into which elastomeric material may subsequently be injected tothereby form the elastomeric parts of the toothbrush. The elastomerparts may be introduced by a subsequent injection moulding step, inwhich the skeleton is enclosed in a second mould having one or morecavity which defines the shape of the elastomer parts, for example thesaid elastomer oral hygiene parts and or other elastomeric parts such aelastomeric parts of flexible links and/or grip enhancing features ofthe handle. Then the elastomeric material is injected into the mouldcavity as a hot fluid and bonds to the plastics material. A suitableinjection moulding process by means of which toothbrushes can be madehaving elastomeric materials disposed at separated places on a plasticsmaterial is disclosed in WO 94/05183 among others.

The elastomeric oral hygiene part(s) may be made by such an injectionmoulding process. It may be convenient to link two or more such parts bymoulding channels in the plastic material of the head so that two ormore elastomeric parts can be moulded fed with fluid elastomericmaterial from a single injection point and thence flow through thechannels in the skeleton, this being known technology. Using suchtechnology the elastomeric material may also be exposed on other partsof the head, for example to form a soft elastomeric buffer around thehead (known in the art), or to form a base from which the elastomericoral hygiene parts may project, and/or the elastomeric material may beexposed on the opposite face of the head for example to form adecorative pattern complementing the appearance of the oral hygienepart(s) on the face. A process of this kind is disclosed inWO-A-00/64307.

The bristles may also be of generally conventional construction,arrangement on the bristle face, and materials, and may be fastened intothe bristle face by generally known techniques. The bristles of thetoothbrush may be fixed into the head by either small metal anchors orfused into the plastics material of the head. These technologies arewell known in the art.

The invention will now be described by way of example only withreference to the accompanying figures which show:

FIG. 1 shows a side view of one embodiment of a toothbrush headaccording to this invention.

FIG. 2 shows a plan view of the embodiment of FIG. 1.

FIG. 3 shows a plan view of another embodiment of a toothbrush headaccording to this invention.

FIG. 4 shows a plan view of another embodiment of a toothbrush headaccording to this invention.

FIG. 5 shows a side view of the toothbrush head of FIG. 3.

FIG. 6 shows a plan view of another embodiment of a toothbrush headaccording to this invention.

FIG. 7 shows a side view of the toothbrush head of FIG. 6.

FIG. 8 shows a plan view of another embodiment of a toothbrush headaccording to this invention.

FIG. 9 shows a plan view of another embodiment of a toothbrush headaccording to this invention.

FIG. 10 shows a plan view of another embodiment of a toothbrush headaccording to this invention, FIG. 10A showing a detailed side view.

FIG. 11 shows an underside view of the toothbrush of FIG. 3.

FIG. 12 shows a plan view of another embodiment of a toothbrush headaccording to this invention.

Referring to FIGS. 1 and 2 a toothbrush head 10 and the immediatelyadjacent part of the neck 11 is shown. The entire toothbrush comprisesthe head 10 and a grip handle (not shown), disposed along a longitudinalhead-handle direction L-L, with the neck 11 longitudinally in betweenthe head 10 and handle. The head 10 is generally elongate between a tip12 distant from the handle and a base 13 closest to the handle. The head10 is flattened in its thickness direction T generally perpendicular tothe longitudinal direction L-L, and has a widthwise direction W-Wperpendicular to both the longitudinal L-L and thickness T directions.

The head 10 comprises two longitudinally sequentially disposed segments14, 15 flexibly and resiliently linked to each other by link 16. Thesesegments 14, 15 are a substantially rigid base segment 14 adjoining thetoothbrush neck 11 and extending from the base end 13 of the head to thelink 16, and a tip segment 15 extending from the tip 12 of the head tothe link 16. The base segment 14 extends for at least 60% of thedistance between the base end 13 of the head and the tip 12 of the head.The face 17 of the tip segment 15 forms an angle of 155°-170° with theface 18 of the base segment.

The link 16 is of a known type as described for example in applicant'sWO-A-97/07707 and as used in the applicant's Dr BEST SENSORKOPF™toothbrushes and comprises a thin leaf (not shown) of plastic materiallinking the segments 14, 15 and completely enclosed in an elastomermaterial.

Between the base segment 14 and the neck 11 there is a resilientlyflexible link 19. This link 19 comprises a thin, flexible plasticmaterial spine (not shown) integrally linking the base segment 14 headand neck 11, wholly or partly surrounded by a surrounding mass ofelastomer with a generally spherical profile. The construction offlexible link 19 is as disclosed in WO-A-97/24949. The face 17, 18 ofthe head has side edges 110, aligned at a shallow convergent angle tothe longitudinal direction L-L.

The overall construction of the head and neck of all the toothbrushesshown in FIGS. 1 to 11 is the same as FIGS. 1 and 2, but different typesand configurations of elastomeric oral hygiene parts and bristles aredisclosed, as discussed below.

Referring to FIGS. 1 and 2, a plurality of elastomeric oral hygieneparts 21 are mounted on the face 17 of the tip segment 15, andconventional bristles 22 are the only oral hygiene parts present mountedon the face 18 of base segment 14.

In FIGS. 1 and 2 the elastomeric oral hygiene parts 21 comprisecylindrical elastomeric fingers, typically ca. 1-1.5 mm diameter, andabout the same length as the conventional bristles 22. Seven of thecylinders 21 are mounted in a polygonal cluster, in the form of ahexagon of the cylinders 21 surrounding a central cylinder 21. As shownin FIG. 1 the fingers 21 extend perpendicularly from the face 17 of thetip segment 15 in a length direction “1”. The elastomeric material ofthe cylinders 21 is integrally extended to cover the face 17 of the tipsegment 15, for example by leaving a suitable cavity in the plasticmaterial “skeleton” of which the plastic material parts of thetoothbrush are made, and into which the elastomeric material issubsequently injected. Such processes are well known.

As shown in FIG. 1 the bristles 22 also extend perpendicularly from theface 18 of the base segment 14, i.e. perpendicularly to both thelongitudinal direction L-L and the width direction W-W. In analternative configuration shown in FIG. 2, the bristles 22 are arrangedin substantially longitudinal rows of tufts, and all the tufts in a roware aligned non-perpendicularly at around ca. 80° to the plane of theface 18. The tufts 22A of bristles in outermost longitudinal rows leantoward the base 13 of the head, and tufts 22B in widthwise inward rowslean toward the tip 12 of the head 10. Consequently as would be seenlooking in the width direction W-W the tufts 22A and 22B are seen tocross each other to form an “X” shape.

Referring to FIGS. 3, 4 and 5, toothbrush heads 10 are shown in plan andin a side view. The overall construction of the head 10 is identical toFIGS. 1 and 2, i.e. a base segment 14 and a tip segment 15, angled asshown in FIG. 1, with a resilient flexible link 16 between them, and aresilient flexible link 19 between the base segment 14 and the neck 11.

Mounted on the tip segment 15 is a polygonal cluster of seven tufts ofbristles 31 in the form of a hexagon of tufts surrounding a centraltuft.

Mounted on the base segment 14 are elastomeric oral hygiene parts 32,each comprising a strip extending in a strip length direction “1” andhaving a cross section cut across the strip length direction “1” of achevron cross section. Each limb 32A, 32B of the chevron is itself inthe form of a strip of elastomeric material extending in the striplength direction, the strips converging to define an angle ca. 90°between them, and integrally formed at the angle of the chevron. Eachlimb 32A, 32B has a strip width direction generally perpendicular to thestrip length direction, and a strip thickness direction generallyperpendicular to both the strip length and strip width direction, thestrip thickness dimension being less than the strip width direction.Each of the limbs 32A, 32B has its width direction aligned at ca. 45° tothe longitudinal direction L-L.

Bristles 33 are also shown mounted on the face 18 of the base segment15. The bristles 33 are arranged on the face 18 in tufts containing aplurality of bristles, shown being of circular cross section cut acrossthe bristle direction, and shown mounted in the head with their bristledirection substantially perpendicular to the face.

As shown in FIG. 3 a plurality of the elastomeric oral hygiene parts 32are arranged along the perimeter of the cluster of bristles 33 and parts32, with the point of the chevron pointing inwardly toward thelongitudinal centre line of the head 10. FIG. 4 shows a headconstruction analogous to that of FIG. 3, but with strips 42 having thepoint of the chevron pointing outwardly away from the longitudinalcentre line of the head 10.

Bristle tufts 33A, 43A are located in the “bite” between the converginglimbs of the strips 32, 42. Although shown as having a circular crosssection such tufts may conveniently have a triangular cross section, sothat they nest neatly into the bite of the chevron section of theelastomer strip 32, 42. About the centre of the cluster of strips andbristles there are further tufts of bristles 33B, 43B arranged in alongitudinal row. The strips 32, 42 project to the same or approximatelythe same length from the face as the bristles 33, 43. The stripthickness dimension is in the range 0.1 to 1.00 mm.

Referring to FIGS. 6 and 7 a toothbrush head 10 is respectively shown inplan and a side view. The overall construction of the head 10 isidentical to FIGS. 1 and 2, i.e. a base segment 14 and a tip segment 15,angled as shown in FIG. 1, with a resilient flexible link 16 betweenthem, and a resilient flexible link 19 between the base segment 14 andthe neck 11.

Mounted on the base segment 14 is a plurality of bristle tufts 61A, 61B,which lean identically as in the tufts of FIG. 2. The tufts 61A ofbristles in outer longitudinal rows lean toward the base 13 of the head,and tufts 61B in widthwise inward rows lean toward the tip 12 of thehead 10. Consequently as is seen looking in the width direction W-W thetufts 61A and 61B are seen to cross each other to form an “X” shape. InFIG. 6 the tufts 61A and 611B are also distanced longitudinally.

Mounted on the tip segment 15, are a plurality of chevron sectionedelastomeric strips 62 with the point of their chevron pointing in adirection parallel to the longitudinal direction away from the handle.Two such strips 62 are shown, longitudinally adjacent to each other,with the point of one nesting into the “bite” of the other which islocated nearer to the tip 12. Also mounted on the tip segment 14 are twogenerally rectangular or flattened oval sectioned strips 63 flankingeach widthwise side of the strips 62. The limbs of the chevron 62 areslightly curved to present a concave surface facing outwardly. Thestrips 62, 63 extend substantially perpendicular to the plane of theface 17 of tip segment 15. As in FIG. 2 The elastomeric material of thestrips 21 is integrally extended to cover the face of the tip segment15.

Referring to FIGS. 8, 9 and 10 a toothbrush head 10 is respectivelyshown in plan and a side view. The overall construction of the head 10is identical to FIGS. 1 and 2, i.e. a base segment 14 and a tip segment15, angled as shown in FIG. 1, with a resilient flexible link 16 betweenthem, and a resilient flexible link 19 between the base segment 14 andthe neck 11. The face 18 of the base segment 15 is stepped to define twolevels, comprising a central longitudinally aligned raised platform 18A,flanked on both widthwise adjacent sides by relatively lower areas 18B.

Mounted on the tip segment 15 of each head 10 is a polygonal cluster ofeight tufts of bristles 31 in the form of an irregular heptagon of tuftssurrounding a central tuft.

Mounted on the central platform 18B of base segment 14, are a pluralityof chevron sectioned elastomeric strips 81 each with the point of theirchevron pointing in a direction parallel to the longitudinal directionaway from the handle. Also mounted on the central platform 18B are aplurality of bristle tufts 82 having a cross section cut across thebristle direction which is of a chevron shape. Each limb of the chevroncomprises a bar of bristles aligned at ca. 45° to the longitudinal axisof the head, and merging at the fold or apex of the chevron, so that thebite of the chevron encloses ca 90°. Each chevron sectioned tuft isaligned like the elastomeric parts 81, i.e. pointing in the longitudinaldirection away from the handle. The parts 81 and tufts 82 are nested,comprising a longitudinal sequence of alternating tufts 82 andelastomeric oral hygiene parts 81. Also mounted on the central platform18A are circular section bristles 83, between the flexible link 16 andthe closest of the parts 81 to tip 12. The strips 81 and tufts 82, 83extend substantially perpendicular to the plane of the platform 18B ofbase segment 14 and are all of substantially the same length.

Mounted on the lower areas 18A of base segment 15 of each of the headsof FIGS. 8, 9 and 10 is a plurality of bristle tufts 84A, 84B, 91, 101.

In FIG. 8 the tufts 84A, 84B are oval sectioned with the long dimensionof the oval parallel to the side edges of the base segment 14. The tufts84A of bristles, are arranged as the outermost longitudinal rows, andlean toward the tip 12 of the head, and tufts 84B in widthwise inwardrows lean toward the base 13 of the head 10, as is shown by the arrowsindicating the direction of lean of one representative tuft of the row.Consequently as would be seen looking in the width direction W-W thetufts 84A and 84B cross each other to form an “X” shape analogous toFIG. 7.

In FIG. 9 the arrangement on the tip segment 15 and central platform 18Bis the same as FIG. 8 so is not described in detail. Tufts 91 arearranged longitudinally on the outer levels 18A. Tufts 91 are ovalsectioned with the long dimension of the oval aligned at ca. 45° to thelongitudinal axis of the head, i.e. approximately parallel to the limbsof the chevrons on the central platform 18B. The long dimensions of thecross sections of widthwise separated tufts 91 converge toward the tip12 of the head. The length to which the tufts 91 extend from the facealternate longitudinally between greater and lesser lengths.

In FIG. 10 the tufts 101 have an elongate cross section cut across thebristle direction in the form of a bristle bar of generally rectangularcross section, with the long dimension of the cross section alignedsubstantially parallel to the longitudinal edges of the toothbrush head10. As shown in FIG. 10A bristles in tufts 101 lean at a nonperpendicular angle toward the tip or the base of the head. At thelongitudinally central position in tufts 101 the bristles are alignedperpendicular to the face 18A. On each longitudinally opposite side ofthis central position the angle of lean progressively increases, to amaximum of ca. 80° at the longitudinal ends of the tufts 101, so thebristles are in a fan-like arrangement.

Referring to FIG. 11, an underside view of the toothbrush head of FIG. 3or 4 is shown, looking at the face 111 opposite to that 18 from whichthe elastomer parts extend. The elastomer parts, i.e. the oral hygieneparts 32, 42 and elastomeric parts of the links 17, 19 are linked bymeans of moulding channels in face 111 and passing through the thicknessT of the head 10, so that the same elastomeric material and single pointinjection thereof may be used.

Referring to FIG. 12 another toothbrush head 120 of this invention isshown in plan view. The entire toothbrush comprises the head 120 and agrip handle (not shown), disposed along a longitudinal head-handledirection L-L, with the neck 121 longitudinally in between the head 120and handle. The head 120 is generally elongate between a tip end 122distant from the handle and a base end 123 closest to the handle. Thehead 120 has a widthwise direction W-W perpendicular to the longitudinalL-L direction. The head 120 is flattened in its thickness direction i.e.in the direction perpendicular to the plane of the drawing.

The head 120 comprises two longitudinally sequentially disposedsegments, 124,125 viz. a substantially rigid base segment 124 adjoiningthe toothbrush neck 121 and extending from the base end 123 of the headto a link 126, and a tip segment 125 extending from the tip 122 of thehead to the link 126. The base segment 124 extends for ca. 65% of thedistance between the base end 123 of the head to the tip 122 of thehead. The face 127 of the tip segment 125 forms an angle of 155°-170°with the face 128 of the base segment 124, i.e. an arrangement similarto FIGS. 1-7 and having a side view (not shown) similar to FIG. 1,5 or7.

The link 126 is of a known type as described for example in applicant'sWO-A-97/07707 and as used in the applicant's Dr BEST SENSORKOPF™toothbrushes. The link 126 comprises a groove in the opposite surface tothe surface 127, 128, which in one or more place 129 cuts completelythrough the thickness of the head 120. In other places the groove cutsonly partly through the thickness of the head 120, leaving a thinresidual flexible leaf 1210 of plastic material, coplanar with thesurfaces 127, 128, linking the segments 124, 125. The groove is filledwith an elastomer material 1211. The elastomer material 1211 is suitablythe elatomer material as known for use in known toothbrushes havingflexibly linked segments.

Between the base segment 124 and the neck 121 there is a resilientlyflexible link 1212 having a construction identical to that of link 19described above.

Mounted on the face 127 of base segment 124 are plural elastomer oralhygiene parts 1213 arranged sequentially longitudinally. These parts1213 each comprise a strip of elastomeric material extending in a striplength direction perpendicular to the plane of the drawing, and having across section of a “V” or chevron shape, however with the limbs of thechevron being slightly curved to present a concave surface outwardly,and the point of the chevron is rounded. The point of each chevronpoints inwardly away from the adjacent outer edge of the face 127. Theangle between the limbs of each chevron sectioned strip 1213 is ca. 60°,and the strip thickness dimension “d” is ca. 0.9 mm.

Also mounted on the face 127 are bristle tufts 1214, 1215, 1216, 1217,1218, 1219. Tufts 1214 are triangular in cross section with an apexpointing inwardly and a base generally parallel to the edge of face 127,and of a shape conforming to and nesting into the “bite” of the chevrons1213. Tufts 1215 are also triangular in cross section and are shapedsuch that their sides are generally parallel to, and nest into thegenerally triangular space between, the limbs of longitudinally adjacentchevrons 1213, with apexes pointing outwardly. Tufts 1216 are of anelongate generally rectangular cross section cut across the bristledirection, the long dimension of the elongate cross section beingaligned parallel to the longitudinal axis L-L of the toothbrush head120. Tuft 1217 is also of a gerally triangular cross section cut acrossthe bristle direction, nesting into the bite between the limbs of twoadjacent chevrons 1212. Mounted on the face 128 of the tip segment arebristle tufts 1218 of a generally rectangular cross section as cutacross the bristle direction. The pattern of tufts 1218 comprise acentral tuft, with adjacent tufts following the perimeter of the face128. Tufts 1219 are of a curved cross section corresponding generally tothe arc of the tip end 122.

The elastomer material of the strips 1212 may pass completely throughthe head 120 and be linked at the opposite face, as shown in FIG. 3.

Typically the elastomeric material of cylinders 21 and strips 32, 42,62, 63, 81, 1213 is a thermoplastic elastomeric material which can beinjection moulded. Typically in its set state the elastomeric materialhas a hardness from about 10 to about 90 Shore A, more preferably 30Shore A or greater, e.g. from about 35 to about 55 Shore A.

1. A toothbrush head having a tip end and a base end, the base end beingconnected or connectable to a toothbrush handle and having alongitudinal direction between the tip end and base end, and having aface, and having an elastomeric oral hygiene part mounted on the face,the elastomeric oral hygiene part comprising an adjacent pair ofelastomeric strips which each project from the face of the toothbrushhead in a strip length direction, each elastomeric strip having a stripwidth direction generally perpendicular to the strip length directionthe strip width dimension being less than the strip length direction,and a strip thickness direction generally perpendicular to both thestrip length and strip width direction, the strip thickness dimensionbeing less than the strip width direction, characterised by two saidadjacent strips linked such that the pair of strips comprise a singleelastomeric oral hygiene part with a cross section, cut across the striplength direction, which is chevron shaped, the limbs of the chevronconverging to define the said angle of less than 180° between them.
 2. Atoothbrush head according to claim 1 characterised in that the adjacentstrips are aligned so that their respective width directions converge todefine an angle of 90-60° between them.
 3. A toothbrush head accordingto claim 1 or 2 characterised by longitudinally adjacent strips in whichthe width directions converge in a direction transverse to thelongitudinal direction of the head.
 4. A toothbrush head according toclaim 1 or 2 characterised by widthwise adjacent strips in which thewidth directions converge in a direction parallel to the longitudinaldirection.
 5. A toothbrush head according to any one of claims 1, 2 or 3characterised in that the chevron points in a direction transverse tothe longitudinal direction.
 6. A toothbrush head according to claim 5characterised in that the chevron points inwardly away from the outeredge of the face.
 7. A toothbrush head according to claim 4characterised in that the chevron points in a longitudinal direction. 8.A toothbrush head according to any one of the preceding claimscharacterized by one or more tuft containing a plurality of bristles,said tuft having a non-circular cross section cut across the bristledirection.
 9. A toothbrush head according to claim 8 characterised inthat said said tuft having a non-circular elongate cross section issubstantially rectangular with its long dimension aligned substantiallyparallel to or perpendicular to the longitudinal direction of the head.10. A toothbrush head according to claim 8 characterised in that saidsaid tuft having a non-circular elongate cross section is triangular insection.
 11. A toothbrush head according to claim 10 characterised inthat said said triangular section tuft nests in the bite between twoadjacent convergent elastomer strips of an elastomeric oral hygienepart.
 12. A toothbrush head according to any one of claims 1 to 11characterised by comprising two or more segments flexibly andresiliently linked to each other, one or more of the segments having aface on which is mounted the said one or more elastomeric oral hygienepart, and/or said head being connected by a resiliently flexible link tothe handle.
 13. A toothbrush head according to claim 12 characterised bytwo longitudinally disposed segments being a substantially rigid basesegment adjoining the toothbrush neck and extending from the base end ofthe head to a resilient flexible link situated between the base end andthe tip, and a tip segment extending from the tip of the head to thelink, the tip segment being flexibly and resiliently linked at the linkto the base segment.
 14. A toothbrush head according to claim 13characterised by plural elastomeric oral hygiene parts each comprising achevron sectioned elastomeric part pointing inwardly away from the outeredge of the head, mounted on the base segment.
 15. A toothbrush headcomprising two or more segments flexibly and resiliently linked to eachother, characterised by one or more of the segments having a face onwhich is mounted one or more elastomeric oral hygiene part.
 16. Atoothbrush head according to claim 15, characterised in that thesegments are longitudinally sequentially disposed.
 17. A toothbrushhaving a head which is connected by a resiliently flexible link to thehandle, characterised by having a face on which is mounted one or moreelastomeric oral hygiene part.
 18. A toothbrush according to claim 17,characterised in that the toothbrush head comprises two or more segmentsflexibly and resiliently linked to each other, one or more of thesegments having a face on which is mounted one or more elastomeric oralhygiene part.
 19. A toothbrush head on which is mounted one or moreelastomeric oral hygiene part, and on which are also mounted bristleswhich lean at a non perpendicular angle to the face, so that the end ofthe bristle remote from the face is distanced longitudinally orwidthwise relative to the end of the bristles closest to the face
 20. Atoothbrush head according to claim 19 characterised in that the bristleslean in a direction generally parallel to the longitudinal direction ofthe head.
 21. A toothbrush provided with a head as claimed in any one ofclaims 1 to 16, or 19 or 20.